Grapple.



NITED sTATEs', PATENT OFFICE.

vHAiavizY FARRINGTON, or YoNKERs, NEW YORK;

GRAPPLE. i

L No. 806,408.

`To all whom it may concern.-

Be it known vthat I, HARHVEY FARRINGTON, a

citizen of the United States, residing at Yon k' ers, in the county of' Westchester, State of New York', have' invented certain new and yuseful Improvements in Grapples, of which the following is a specification, reference being had therein t'o the accompanying drawings, in which Figure 1 `is a side elevation of the device applied, showing the expansible gripping device in section; Fig. 2, a side elevation of the gripping device as it isrst formed and showing it tapered internally and externally; Fig. 3, fa sectional viewof the said device after it is cut to make its outer diameter uniform, and Fig. 4 a detail sectional viewof a portion of the expander.

One of the many objects of.v this invention is to provide a grapple of Avery'simple construction which may be 'used instead ofthe ordinary lewis and which may be placed in an aperture "having parallel ywalls-such, for illstance, asis formed` by the ordinary rockdrill.

A further object ofv the invention is to provide 'such a device of simple-construction which .may be temporarily secured in -operative' position by simply rotating the expander vin the expansible keeper or gripping device,

said gripping device being preferably first applied to the expander and the two parts thus engaged `inserted inthe aperture prepared to receive them. f Y A lt-is intended that the device may be used as an expanding-bolt, ify desired ,andas a'wedge or expanding device by means of which blocks of stone or other material may be split. Itis obvious that there are other uses-to which this. device may be put and. which will readily suggest themselves tothose using this` class of angle with -respect to the central line of the. expander, while at its otherendit is parallel with said central line. 1t will thus'be seen that this spiral vwedge 7face orexpander-cam Specification of Letters Patent. Application inea may 27, 1905. seria No. 262,695.

Patentea nec, 5, 1905.

spect to the central line of the expander, this Y angle being gradually reduced until at the other end of said cam-it is merged into the parallel 'sides of the expander. The result of thisA construction is to gradually lessen the height of the should er 5 formed'by'the thread,

` said shoulder being greatest at the entering endof the expander and graduallygrowing less toward the other end thereof. This shoulder is perpendicular to the axisof the expander and forms a positive stop for the keeper to prevent it moving outwardon the expander when the device is being forced into an aperture prepared to receive it.

The purpose of"changingjhvegaiigle of the expanden-*cam fis to reduce the shoulder 5,

face of the cam.l The object of Varyingthe height of the shoulder 5 isto provide an expander-which will actquickly on the upper coil of the keeper-'when' a strain is placed upon the' expander tending to draw it from the keeper. It will-be readily seen that the coils of the keeper` will move over the -expanderof the expander much more readily than over the face of the cam at the end of the expander.- The result of this is that when the strain is first placed upon the expander the coils at the .while at'the same time' maintain the broad\ :cam face atthe upper end of the tapered part top of the keeperwill be first expanded,while the coils atthe bottom thereof will move slightly upward. Y As the strain increases on l the expander the coils of the keeper will gradually expand fromthe upper 'end of the keeper downwardA until `the friction of the keeper against the wall of the aperture in which it is placed is sufflcienttohold the keeper therein and permit the expander to lift the ,block of stone or other article inwhich said keeper is placed. From this itis clear that the keeper is caused to progressively engage the Wall of IOO IIO

coils thereof to -Hrmly grip thewall 0f the keeper are of thinner material than the lower coils thereof and are consequently more easily expanded. It will also be Seen that the flat surfaces of these upper coils engage the wall of the aperture in which the keeper is to be used. It is clear that the upper portion of the expander-cam will slide through the coil because of the slight angularity of said cam, thereby causing said coils to frictionally engage the wall of the aperture. Itis also clear that because of the angle of the lower coils of the expander-cam the lower coils of the keeper will first slide upward in the aperture until the expansion of the keeper has progressed from its upper to its lower end. The lower coils of the keeper being comparatively stiff will be more apt to slide up in the aperture than the upper coils thereof, which will more readily yield to the force exerted by the expander-cam.

As the expander is tapered, it is evident that an expansible keeper or gripping device must be provided having its interior tapered to l`correspond substantially to the taper of the threaded end of the expander. It is also clear that this gripping device or keeper must have parallel outer sides-that is, it must be equal in outside diameter throughout its length in order that it`may be used in apertures having parallel walls. The gripping device 6'(shown in Fig. 3) is tapered internally to correspond substantially to the taper of the expander; but it is of equal outside diameter throughout its length. This keeper is formed of wire or a strip of other suitable material, preferably of soft steel wire of the proper gage and temper wound upon a tapered mandrel, said mandrel corresponding in taper to the taper of the expander, or it may be wound upon the expander so that the interior of the spiral keeper will be tapered to correspond to the taper of the expander. When the keeper is withdrawn from the mandrel, its outside diameter varies from end to end, as shown in Fig. 2. As thus formed it is placed in a lathe or other device and turned or ground down until its outside diameter is equal throughout its entire length, as shown clearly in Fig. 3. It will therefore be seen that the material of the keeper at one of its ends will be much thinner and more resilient than at the other end and that said thinner end will expand more readily than the other parts of the keeper. 1t will also be noted that the material of the keeper at the lower end thereof-that is, at its smallest internal diameter-is circular in cross section and that at the opposite end thereof it is segmental in cross-section, with its fiat side forming a portion of the outer side of the coil and adapted to contact with the wall of the aperture prepared to receive it. By reference to Fig. l it will be seen that the material of the coil of the smallest section in cross-section is arranged on the expander in such a position that it will be engaged by that portion of the face of the expander-cam having the least angle. It will be also noted that the spiral shoulder formed by the spiral thread Will be correspondingly reduced by the change in the angle of the face of the thread, so that the outer surface of the keeper will at all points project beyond the shoulder.

When the parts are arranged as shown in Fig. 1, the keeper will be forced by the inward inclination of the cam face or thread upward against the shoulder, and any strain tending to withdraw the expander from the keeper will tend to cause the keeper to ride outward on said inclined face of the expander-cam and against the walls of the aperture in which the device is temporarily secured. As the keeper or gripping device is in the form of a coil, it is obvious that the extent of the gripping or frictional surface is equal to the length of the material `forming the coil. It is also clear that when a strain is applied to the expander tending to draw it out of the keeper the upper end of the keeper will be first expanded, as it will yield more readily than the lower part thereof. This outward expansion will contract the keeper longitudinally and will be gradually distributed throughout the length of the keeper as the outward pull on the expander is increased.

It is obvious that the coil and the expander may be made of any desired length and of any diameter to suit it for the work for which it is designed. I have found that an expander one inch in diameter with its corresponding keeper is ample for lifting loads as high as six or eight tons and that with an expander and keeper of one and one-half inches in diameter as much as thirty tons may be lifted with perfect safety.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. A grapple comprising an expander tapered toward one end and formed at said tapered portion with a spiral thread or expandercam having a face whose angle varies from end to end, whereby a spiral shoulder is formed varying in height from end to end, and a coiled keeper or gripping device adapted to be engaged by said spiral expander-cam, said keeper varying in internal diameter to correspond substantially with the tapered part of the expander, the exterior diameter of said keeper being uniform throughout.

2. A grapple comprising an expander talIO pered at one end and formed at said tapered part with a single broad-faced spiral thread or expander-cam whose angle varies from end to end, the face of said cam at the end of the expander being at an acute angle with respect to the longitudinal center line of the expander,

its opposite end merging into the side of the expander at the end of the tapered part thereof, and a coiled keeper or gripping device varying in internal diameter to correspond to the`taper of the expander, the external diameter of said gripping device being uniform throughout its length, whereby the said keeper may be inserted in an aperture havingparallel Walls. f

3. A grapple comprising, an expander formed at one end with a broad-facedk spiral thread or expander-cam, the face of said cam at the entering end of the expander being at an acute angle with respect to the longitudinal line of the expander and gradually lessening its angle to its other end, and an internally -tapered expansible gripping device l adapted to be engaged by the expander-cam,

the external diameterfof said gripping device being uniform throughout its length.

, 4. A grapple comprising an expander v formed at one end with a single broad-faced spiral thread or expander-cam of uniform pitch from end to end, the face of said cam at the end of the expander being. at an acute angle with respect to the longitudinal line of. the expander and gradually lessening its angle to the opposite end of said cam, and a coiled gripping device varying in internal diameter and adapted to be engaged by the spiral exa.

5. A gripping device for. a grapple consistf i ing of a coiled strip of suitable material whose internal diameter varies from end to end and whose external diameter is uniform throughout, in combination with an expander formed with a single-faced spiral expander-cam or thread adapted to engage said coil throughout its length. s

6. A keeper or gripping device for a grap= ple and similar devices formed of a coil of suitable material circular in cross-section at one of its ends, and gradually flattened toward its other end, said other end of said material being segmental in cross-section, said material being so coiled that the attened portion thereof will form a portion of the exterior of said coil, the internal diameter of said coil varying from end to end 'and the external diameter thereof being uniform throughout its length.

7. ,A grapple comprising an expander tapered at one end and formed at said tapered part with acne-faced broad spiral thread or expander-cam, a shoulder being formed by said thread perpendicular to the axis of the expander, and acoiled keeper varying in internal diameter to correspond to the taper of the :expander and adapted to be engaged throughout its length by the expander-cam 'and to normally lie against the said shoulder.

In testimony whereof I hereunto affix my signature,'in the presence of two witnesses,

this 26th day of May, 1905. HARVEY FARRINGTON.

Witnesses: y

WVM. R. DAvIs, W. H. RUBY. 

